<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8"/>
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no, viewport-fit=cover"/>
<meta name="description" content="Example custom PanelLayout."/> 
<link rel="stylesheet" href="../assets/css/style.css"/> 
<!-- Copyright 1998-2021 by Northwoods Software Corporation. -->
<title>PanelLayout GoJS Sample</title>
</head>

<body>
  <!-- This top nav is not part of the sample code -->
  <nav id="navTop" class="w-full z-30 top-0 text-white bg-nwoods-primary">
    <div class="w-full container max-w-screen-lg mx-auto flex flex-wrap sm:flex-nowrap items-center justify-between mt-0 py-2">
      <div class="md:pl-4">
        <a class="text-white hover:text-white no-underline hover:no-underline
        font-bold text-2xl lg:text-4xl rounded-lg hover:bg-nwoods-secondary " href="../">
          <h1 class="mb-0 p-1 ">GoJS</h1>
        </a>
      </div>
      <button id="topnavButton" class="rounded-lg sm:hidden focus:outline-none focus:ring" aria-label="Navigation">
        <svg fill="currentColor" viewBox="0 0 20 20" class="w-6 h-6">
          <path id="topnavOpen" fill-rule="evenodd" d="M3 5a1 1 0 011-1h12a1 1 0 110 2H4a1 1 0 01-1-1zM3 10a1 1 0 011-1h12a1 1 0 110 2H4a1 1 0 01-1-1zM9 15a1 1 0 011-1h6a1 1 0 110 2h-6a1 1 0 01-1-1z" clip-rule="evenodd"></path>
          <path id="topnavClosed" class="hidden" fill-rule="evenodd" d="M4.293 4.293a1 1 0 011.414 0L10 8.586l4.293-4.293a1 1 0 111.414 1.414L11.414 10l4.293 4.293a1 1 0 01-1.414 1.414L10 11.414l-4.293 4.293a1 1 0 01-1.414-1.414L8.586 10 4.293 5.707a1 1 0 010-1.414z" clip-rule="evenodd"></path>
        </svg>
      </button>
      <div id="topnavList" class="hidden lg:text-base sm:block items-center w-auto mt-0 text-white p-0 z-20">
        <ul class="list-reset list-none font-semibold flex justify-end flex-wrap sm:flex-nowrap items-center px-0 pb-0">
          <li class="p-1 sm:p-0"><a class="topnav-link" href="../learn/">Learn</a></li>
          <li class="p-1 sm:p-0"><a class="topnav-link" href="../samples/">Samples</a></li>
          <li class="p-1 sm:p-0"><a class="topnav-link" href="../intro/">Intro</a></li>
          <li class="p-1 sm:p-0"><a class="topnav-link" href="../api/">API</a></li>
          <li class="p-1 sm:p-0"><a class="topnav-link" href="https://www.nwoods.com/products/register.html">Register</a></li>
          <li class="p-1 sm:p-0"><a class="topnav-link" href="../download.html">Download</a></li>
          <li class="p-1 sm:p-0"><a class="topnav-link" href="https://forum.nwoods.com/c/gojs/11">Forum</a></li>
          <li class="p-1 sm:p-0"><a class="topnav-link" href="https://www.nwoods.com/contact.html"
           target="_blank" rel="noopener" onclick="getOutboundLink('https://www.nwoods.com/contact.html', 'contact');">Contact</a></li>
          <li class="p-1 sm:p-0"><a class="topnav-link" href="https://www.nwoods.com/sales/index.html"
           target="_blank" rel="noopener" onclick="getOutboundLink('https://www.nwoods.com/sales/index.html', 'buy');">Buy</a></li>
        </ul>
      </div>
    </div>
    <hr class="border-b border-gray-600 opacity-50 my-0 py-0" />
  </nav>
  <div class="md:flex flex-col md:flex-row md:min-h-screen w-full max-w-screen-xl mx-auto">
    <div id="navSide" class="flex flex-col w-full md:w-48 text-gray-700 bg-white flex-shrink-0"></div>
    <!-- * * * * * * * * * * * * * -->
    <!-- Start of GoJS sample code -->
    
    <script src="../release/go.js"></script>
    <div class="p-4 w-full">
    <script id="code">
    function PanelLayoutCascading() {
      go.PanelLayout.call(this);
      this.name = "Cascading";
    }
    go.Diagram.inherit(PanelLayoutCascading, go.PanelLayout);

    /**
     * Given the available size, measure the Panel and
     * determine its expected drawing size. Sets the measuredBounds of the object.
     *
     * This must call {@link #measureElement} with each Panel element.
     *
     * This must also construct the union.width and union.height of the passed in union Rect argument.
     *
     * @this {PanelLayout}
     * @param {Panel} panel Panel which called this layout
     * @param {number} width expected width of the panel
     * @param {number} height expected width of the panel
     * @param {Array.<GraphObject>} elements Array of Panel elements
     * @param {Rect} union rectangle to contain the expected union bounds of every element in the Panel. Useful for arrange.
     * @param {number} minw minimum width of the panel
     * @param {number} minh minimum height of the panel
     */
    PanelLayoutCascading.prototype.measure = function(panel, width, height, elements, union, minw, minh) {
      var l = elements.length;
      for (var i = 0; i < l; i++) {
        var elem = elements[i];
        this.measureElement(elem, width, height, minw, minh);
        var mb = elem.measuredBounds;
        union.width += mb.width;
        union.height += mb.height;
      }
    }

    /**
     * Given the panel and its list of elements, arrange each element.
     *
     * This must call {@link #arrangeElement} with each Panel element, which will set that element's {@link GraphObject#actualBounds}.
     *
     * For arranging some elements, it is useful to know the total unioned area of every element.
     * This Rect can be used to right-align or center-align, etc, elements within an area.
     *
     * @this {PanelLayout}
     * @param {Panel} panel Panel which called this layout
     * @param {Rect} ar arranged bounds of the panel
     * @param {Array.<GraphObject>} elements Array of Panel elements
     * @param {Rect} union rectangle, if properly constructed in {@link #measure}, that contains the expected union bounds of every element in the Panel.
     */
    PanelLayoutCascading.prototype.arrange = function(panel, elements, union) {
      var l = elements.length;
      var x = 0;
      var y = 0;
      for (var i = 0; i < l; i++) {
        var elem = elements[i];
        var mb = elem.measuredBounds;
        this.arrangeElement(elem, x, y, mb.width, mb.height);
        /*
        * By incrementing the arranged x and y by the width and height, we arrange each object in a diagonal fashion:
        *  A
        *    B
        *      C
        *        D
        */
        x += mb.width;
        y += mb.height;
      }
    }

    // Register the PanelLayout so that go.GraphObject.make can use it by name:
    go.Panel.definePanelLayout('Cascading', new PanelLayoutCascading())


    function init() {
      var $ = go.GraphObject.make;

      myDiagram =
        $(go.Diagram, "myDiagramDiv",
          { "undoManager.isEnabled": true });

      // Define a simple Node template that includes a Cascading Panel holding
      // some number of item Panels holding Shapes, based on data.items being an Array
      // of item descriptor objects.
      myDiagram.nodeTemplate =
        $(go.Node, "Auto",
          { width: 100, height: 100 },
          $(go.Shape,
            { fill: "transparent", strokeWidth: 2 },
            new go.Binding("stroke", "color")),
          $(go.Panel, "Cascading",
            new go.Binding("itemArray", "items"),
            {
              itemTemplate:
                $(go.Panel,
                  $(go.Shape,
                    { width: 20, height: 20, strokeWidth: 0 },
                    new go.Binding("figure", "fig"),
                    new go.Binding("fill", "color"))
                )
            })
        );

      myDiagram.model = new go.GraphLinksModel(
        [
          {
            key: 1,
            color: "lightgreen",
            items: [
              { fig: "RoundedRectangle", color: "lightblue" },
              { fig: "Triangle", color: "pink" }
            ]
          },
          {
            key: 2,
            color: "lightblue",
            items: [
              { fig: "RoundedRectangle", color: "lightgray" },
              { fig: "Square", color: "yellow" },
              { fig: "Circle", color: "orange" }
            ]
          },
          {
            key: 3,
            color: "purple",
            items: [
              { fig: "Diamond", color: "red" }
            ]
          },
          {
            key: 4,
            color: "orange",
            items: [
              { fig: "Circle", color: "green" },
              { fig: "Square", color: "blue" },
              { fig: "Triangle", color: "red" },
              { fig: "TriangleRight", color: "green" }
            ]
          }
        ]);
    }
    window.addEventListener('DOMContentLoaded', init);
  </script>

<div id="sample">
  <!-- The DIV for the Diagram needs an explicit size or else we won't see anything.
       This also adds a border to help see the edges of the viewport. -->
  <div id="myDiagramDiv" style="border: solid 1px black; width:400px; height:400px"></div>
  <p>
    This sample demonstrates creating a simple custom <a>PanelLayout</a>. It merely cascades the elements diagonally,
    as if combining a Horizontal and Vertical panel.
  </p>
  <p>
    Creating your own Panel layouts is very uncommon, and you should not need to create your own to use GoJS effectively.
    However there may be apps that require creating a custom Panel layout because the standard panel layouts
    do not offer the precise behavior that you want.
  </p>
</div>
    </div>
    <!-- * * * * * * * * * * * * * -->
    <!--  End of GoJS sample code  -->
  </div>
</body>
<!--  This script is part of the gojs.net website, and is not needed to run the sample -->
<script src="../assets/js/goSamples.js"></script>
</html>
